How to check if an object at on a specific position/how to get the position of an object
I actually found out now, if someone needs to know, this is how I get the positions:

import bge
import GameLogic as g

cont = g.getCurrentController()
own = cont.owner
pos = own.position
x = pos[0]
y = pos[1]
z = pos[2]

and this is how I check for them:
if x = 3.0 and 2.5 and y == 3 and z == 2.5:
    print("The object has the coordinates (3.0|2.5|2.5)")